Pipe line plugs



March 26, 1957 E. F. MoRRlLL, .l l l 2,786,489

' PIPE LINE PLUGS Filed sept. 1e, 1954 5 sheets-sheet 1 lllllll ki i-i--F ef ull S i l l l I n u lL Uf) Q N m E S GO E JNVENTOR.

Edward Franc'is Marr/Mdr.

ATTORNEYS March 26, 195 E. F. MORR1| ,JR

PIPE LINE PLUGS 5 Sheets-Shea?l 2 Filed Sept. 16, 1954 N .mi

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RN hwN KN IN V EN TOR. Edward F fonc/'s Mo rr/`//, Jr.

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Y ATTORNEYS March 26, 1957 E. F. MoRRlLL, JR 2,786,489

PIPE LINE PLUGS Filed sept. 1e, 1954 5 sheets-sheet s IN V EN TOR. Edward F rar/cis Morrill, Jr.

ATTORNEYS March 26, 1957 E. F. MoRRlLL, JR

PIPE LINE PLUGS 5 Sheecs-Sheerl 4 A Filed Sept.

Y MWI/AFI..

Edward Franc/'s Morrill, Jr.

A TTRNE YS March 26, 1957 E. F. MORRILL, JR

PIPE LINE PLUGS 5 Sheets-Sheet 5 Filed Sept. 16, 1954 INVENTOR. Edward Francis Morrill, Jn

A TTORNE YS PIPE LINE PLUGS Edward Francis Morrill, Jr., Longview, Tex., assgnor to Mid-Valley Pipeline Company, Longview, Tex., a corporation of Ohio Application September 16, 1954, Serial No. 456,517

17 Claims. (Cl. 13S-89) This invention relates to new and useful improvements and methods and means for plugging pipe lines at selected points.

There have come into use many fluid transmission pipe lines through which uids such as crude oil, lubricating oil, natural gas, and gasoline, and other marketable gases and liquids are flowed for transportation from one area to another. Many of these transmission lines or pipe lines are of considerable length, and it is quite customary for a pipe line to extend several hundred miles or more for the transportation of fluids between various geographic localities.

It is also customary for such pipe lines to be of considerable diameter or of such size that their cross-sectional areas are measurable in square feet rather than in square inches. Obviously, ttings, such as valves, for such large diameter pipe lines are quite expensive, and a length of ten miles of pipe line or titty miles of pipe line will contain an enormous quantity of liuid when the pipe line is full and operating.

Due to the quite considerable cost of large diameter valves, pipe lines are not equipped with shut oli valves every mile or so, and it is quite usual for a pipe line to contain no valve or other shut oit means for a distance of lifty or seventy-live miles or more. Hence, in the event of damage to a pipe line or an arising need for modification or structural change to a pipe line at a given point, a very serious problem arises as to the manner in which the flow of uid through the pipe line is to be controlled during repair or alteration.

Assuming an average installation in which a pipe line of twenty-four inch diameter pipe is devoid of valves for a distance of fty miles, and assuming that a break occurs at the center of this section or a need arises for modifying the pipe line at that point, such as installing an additional pumping station, it would be lcompletely infeasible to use the existing valves for isolating that section of the pipe line due to the tremendous quantity of liquid therein. Assuming the pipe line to be full of crude petroleum, the least valuable liquid likely to be passing through the pipe line, there would still be a body of liquid of tremendous value contained within such a section of pipe, `and the economic loss of discarding this liquid could not be tolerated even if a point of disposal :could be found. Draining of this section of pipe into tanks, tank cars, or tankl trucks, would be quite expensive; and probably quite impractical. Hence, repair or modification of the pipe line under these conditions, while not impossible,lwould be a lengthy and costly operation.

In view of the foregoing, it is the principal object of this invention to provide an improved pipe line plug adapted to be transported through a pipe line to a desired point and there expanded in order to close oit the pipe line as desired.

A particular object of the invention is to provide an improved pipe line plugging device which may be introduced into a pipe line and passed therethrough or therein United States Patent O d 2,786,489 Patented Mar. 26, i857 ICC to desired points, at which points the plug may be selectively expanded and :contracted so as to withstand pressure dierentials acting from either end of the plug, and so as to provide a complete seal or seals at any selected point or points in the pipe line, the plugging device being releasable after use for further passage through the pipe line to a point of removal therefrom.

Still another object of the invention is to provide an improved pipe line plugging device which may be introduced into a pipe line at a point remote from the desired point of plugging, transported through the pipe line to the selected point, therer expanded into sealing condition, and subsequently released and transported through the pipe line to a point remote from the pointv of plugging, with provision for removal of the plugging device at the latter remote point.

Yet another object of the invention is to provide an improved method and means of the character described, wherein small diameter openings may be cut into a pipe line for introduction thereinto of means for blocking the passage through the pipe line of a pipe plugging device, as Well as means for selectively expanding and contracting the pipe plugging device within the pipe line.

An important object of the invention is to provide an improved method for plugging pipe lines at selected points wherein a plugging device is introduced into a pipe line and transported therein to the selected point, and is there expanded to form a plug through the wall of the pipe through a relatively small diameter opening, the plugging device subsequently being released or contracted and further transported through the pipe line for removal therefrom.

A particular object of the invention is to provide a device of the Icharacter described having pressure relieving means for limiting the pressure dilferential across the plugging device, thereby protecting the device against excessive dierentials; and wherein such pressure relieving means is rendered inoperative and incapable of opening under pressure dilerential when the pipe plugging device is expanded into sealing position.

A construction designed to carry out the invention will be hereinafter described together with other features of the invention.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings, wherein an example of the invention is shown, and wherein:

Fig. 1 is a longitudinal, sectional View of a section of pipe line, portions of the structures being shown in elevation, the view illustrating a method and means constructed and carried out in accordance with this invention for sealing off and isolating a section of pipe line for repair or alteration,

Fig. 2 is an enlarged longitudinal view, partly in elevation and partly in section, of a plugging device constructed in accordance with this invention and showing the device in an unexpanded position,

Fig. 3 is a View similar to Fig. 2 showing the device within a pipe line and expanded into sealing position therein,

Fig. 4 is a longitudinal View, partly in elevation and partly in section, of the plug expanding means,

Figs. 5,16, and 7, are sectional views taken upon the respective lines of Fig. 4,

Fig. 8 is a schematic view illustrating the means for introducing the pipe plugging device into a pipe line and removing the same therefrom,

seat mounting. f

Referring now to the drawings in which a specilic ernbodiment of the invention is shown, it is to be noted that a gas or Aiquid transmission pipe line is normally a one-way system in that fluid is normally transported therethrough in 'one direction only. Custoi'narily, pumping stations are provided at intervals in the pipe line, the closeness of the pumping station spacing being dependent upon the iluids being handled, the 'size and nature of the pipe line as well as the terrain it traverses, the pressure drops encountered, the volumes being handled, and so forth. To a considerable extent, all of the pipe line equipment and appurtenances are concentrated at the pumping stations. Between pumping stations, lthe pipe line consists almost exclusively of a number of miles of pipe buried in the ground and having shut ott valves at very rare intervals.

The 'present invention contemplates the introduction und removal of plugging devices into the lpipe line, and the means for such introduction and removal will normally be located at each of the pumping stations. it is the present practice to send Scrapers and other devices through a pipe line and hence, the means for introducing and removing a closure plug into and from lthe 'pipe line already exists in most instances.

in Figs. 8 and 9, a typical installation is shown of the sending and receiving traps for inserting into a pipe line a scraper or pigj or the sealing device of this invention, as well as for removing the same from the pipe line. Generally, the bulli. of the pipe line lil is buried under ground, as shown at ll, and the scraper or plug traps lf. are elevated above ground level and connected into the pipe line l@ 'through gently curving sections 13 which merge into the pipe line lli without the presence of any sharp turns or corners. Obviously, this is done so that the plug or scraper may move smoothly into the pipe line proper without likelihood of becoming lodged upon obstructions or sharp turns in the entrant section. The fluid or liquid under pressure being pumped into the pipe line from the pumping station (not shown) enters the pipe line lil through a branch or lateral conductor l14 of similar size, and there is provided a branch or bypass conductor l extending between the conductor 14 and the trap l2. rthe bypass conductor carries a plug or shut oil valve lo, full opening line valves 17 and 18 are provided respectively between the conductorA 15, downstream of the bypass conductor l5' and the pipe line 10, and the trap l2 and the Vsaid pipeline lll.

rthe trap l2 has its open end closed by a 4readily removable cover plate or cap 19 which ymay ybe removed to expose the open end of thetrap for insertion of the plugging device thereinto. Then, upon replacement of the cap i9?, the opening of the valves 't3 and 16 and the closing or the valve 17, liquid under .pressure is forced from the conductor lili through the bypass conductor 15 and into the trap l2. The iluid thus picks up the plugging device and ows it under pressure through the section ld and the valve 13 into the pipe line lil, after which the valve may be opened and the valves 16 and -18 closed. Thus, the plugging device is introduced into the pipe line and is driven along therethrough with the liquid being pumped through the pipe line.

Subsequently, after the plugging device has vperformed its function and it is desired to remove the same from the pipe line, its passage through the pipe line under the impetus of the flowing liquid is continued until the plugging device reaches the receiving trap of a pumping station such trap being shown in the right hand portion of Fig. 8.

The receiving trap is approximately aV-mirror image of the sending trap and includes the trap 12', 'the gently curving entrance section 13', the valves Y16', QT and 18, as well as the cap member 19', and the bypass conductor l5". Normally, the sending and receiving ytraps ditfer only in that the V'bypass conductor 15 ofthe sending trap is connected into the trap adjacent the cover mem- 4 ber 19, while the bypass conductor l5 of the receiving trap is connected into the trap near its 'point of merging into the entrant section 13'.

Prior to the time the plugging device reaches the receiving trap (and this may be calculated due to the known volume of flow through the pipe line) the valves 1S and 16 are opened, and the valve 1'7 is closed. Thus, the plugging device is caused to pass into the trap 12 while the liquid is bypassed from behind the plugging device through the bypass conductor l5 into the pipe 14 for passage to the pumping station or other installation present at the locality. After the catching of the plugging device in the trap, the valve 17' may be opened and the valves 16 and lli closed to restore completely normal operation. v Upon opening of the cover 19 and the draining of liquid from the trap into the sump 2li', the plugging device may readily be removed.

The means for inserting and removing plugging dcv'ice's 'fro'm the pipe lines has been described lprior to description of the device itself in order to make provision for a clearer explanation of the operation of the plugging device.

Assuming that the sending and receiving traps of Fig. 8 are located at two consecutive pumping stations in a pipe line, that such pumping stations are spaced apart a distance vof seventy-tive miles, and that no other line valves are present in the pipe Vline lll between these pumping stations, it is apparent that no control of the liquid ilo'w Vthrough Vthe pipe line at points between the pumping stations is possible. Assuming further that it is desirable to install 'an additional pumping station midway between the first two stations in order to provide a thirty-seven and 'a half mile 'spacing between stations, it becomes necessary to 'cut into the Vpipe line at this midpoint and to make numerous 'modifications 'for connection of the pumping V'station into the pipe line. In this eventuality, the plugging `device of the present invention is introduced into the pipe line through the sending trap and is pumped therethrough with the liquid normally flowing through the pipe line until it reaches the point at which plugging or closinglff ofthe pipe line is desired.

While various types of plugging devices may be passed through a pipe line in this manner, there is shown in Figs. 2 vand 3 'ia particular embodiment of a plugging device which has been -found highly effective. 'if he device, which will berefe'rre'd t0 as aplug, includes an elongate tubular core 21 having internal, longitudinal stiriening ribs 22. The mandrel `21 is open at each end and is of somewhat less `diameter than the pipe line lt) within `which the plug -is received. While the plug will travel in either direction ina pipe line under the iniiuence of a su'ihcient pressure differential, 'and while it will seal against a pressure acting fro'm either 'end "of the plug, in normal operation the plug travels to "the left, as viewed in Fig. 2, and hence, the left hand end ofthe plug will be referred to herein as the front end of the plug, While the right hand end will be referred t-o as the rear or `trailing end. T he `front end of the mandrel 2li carries an internal annular llange -23 to which there is 4bolted a bearing collar Stil and a tubular cup assembly 25.

The cup assembly 25 comprises essentially an internal sleeve y26 having 'on its outer periphery series of spaced resilient `cups 27, forrned 'of rubber or some other suitable material 'and provided with pressure sealing lips 2i? facing toward the lrearward end of the plug. The cups are orr such diameter Vvas to lit 'snugly ywithin the inner-diameter of the pipe line l0, and are held upon the sleeve 2,6 between annular rings 29 through which elongate securing bolts 30 extend and between which spacer sleeves 3l are positioned. The forward end of the sleeve 26 carries an internal lannular flange 32 to `which a striker plate 33 is bolted. Removal of the plate 33 permits access to the bolts l3l) and complete disassembly of the cup section 25.

An externallythreaded sleeve 34 is slidably received upothe forward section of the mandrel 2l and has bolts 35 projecting inwardly from its rearward, unthreaded section through longitudinal slots 36 cut in the wall of the mandrel 21. The slots extend parallel to the longitudinal -ax-is of the mandrel and lthus permit longitudinal movement of the sleeve 34 upon the mandrel while preventing relative rotation between the two elements.

For effecting longitudinal movement of the sleeve 34, an internally screw-threaded collar 35' is threaded thereon, the collar having an voutwardly projecting annular ange 36 to which is bolted the internal flange 37 of a wide, annular gear 3S. The collar 35 is positioned wit-hin the rearward portion of the gear 38 to provide support therefor, and an annular bearing ring 39 Ais secured to the forward end of `the gear and engages the bearing collar 24. As shown in Fig. 2, the collar 24 has an annula-r internal ilange 40 by which -it is lbolted lto the iiange 23, is counter'- bored to receive the forward end of the sleeve 34, and is provided with an annular external lip 41 at its rearward extremity against which the ring 39 abuts and which prevents rearward movement -of the gear 38 with respect to the mandrel 2l. A spacer ring 4.2, securedv to the cup assembly 25, projects rearwardly around the bearing collar 24 and engages the bearing ring 39 to prevent forward movement of the gear 35.

As will appear more -fully hereafter, means is provided for engaging the gear 38 and rotating the same upon the mandrel 21, thereby forcing the sleeve 34 to move rearwardly over the mandrel.

-A conical wedge or expander drum 43 surrounds and is secured to the rearward portion of the sleeve 34, the smaller end of -the drum facing rearwardly of the plug and engaging in the forward portion of the conical bore 44 of an annular sealing or packing rubber 45. A gusset reinforced flange 46 is welded or otherwise affixed upon the mandrel 21 adjacent the rearward face of the rubber 45 land has clamped thereto an annular rubber backing ring 47 by means of bolts 48 which extend through the ilange 46 and the ring, and which urge against the ring the annular mounting plate 49 Vof a rearward cup section 50. The outer periphery of the ring 47 is spaced relatively closely to the inside wall of the pipe line 10, and the ring abuts the base or rearward face of the rubber 45 to prevent rearward movement thereof as the drum 43 moves rearwardly within the rubber `to expand the same. Thus, the rubber may be forced outwardly into tight sealing engagement with the inner wall of the pipe 10 to provide an etlicient and certain closure of the pipe line.

The structure of the rearward cup section 50 is basically the same as that of the forward cup section 25 and will not be described in detail. The cup section 50 includes a plurality of sealing cups 51, substantially identical to the cups 27 and having rearwardly-facing sealing lips 52 which are adapted to engage the inner wall of the pipe line as the plug passes therethrough. lt is through these cups 5l and 27 that the pressure of the liquid ow-ing through the pipe line is caused to drive the plug through the pipe line to the desired location. Like the forward cup section 25, the rearward cup section 56B has a striker plate 53 provided at its rearward extremity, and is generally tubular in nature in order that tluid may pass readily through ythe center thereof.

In order to prevent the leakage of lfluid through and around the packing rubber 45, lthe heads 54 of the bolts 48 are idesirably welded to the ilange `46, and in addition, a sealing gasket 55 is positioned between the ilange 46 and the ring 47. lEurther, a short cylindrical sleeve 56 cncompasses the outer periphery of the llange46 and projects from the ring 47 forwardly into the tapered or conical bore 44 of the rubber 45. An auxiliary sealing ring 57 of right triangular cross-section fits snugly around 4the outer periphery of the sleeve 56 and abuts the ring 47. The rubber 45 has its rearward inner corner chamfered at 58 to provide space for the mounting of the ring 57. Thus, when the rubber 45 is expanded into sealing engagement with the wall of the pipe line 10, the sealing ring 57 6 functions to preventleakage between the rubber 45v and the ring 47 The rearward end of the mandrel 21 projects to approximately the medial porti-on of the rearward cup sec-tion 50 and is received at that point within an internal annular flange 59 carried by the cup section and centering the rearward extrem-ity of the mandrel therew-ithin. An internal annular flange 60 is welded in the rearward end of the mandrel and has bolted thereto a valve seat ring 61 having a central, rearwardly tapering valve seat 62. A sealing gasket 63 `is confined Ibetween the flange 60 and the ring 61 by the bolts 64, lthe heads 65 of which engage O-ring .seals 66 carried in chamfers formed around the bolt openings in the ring 61. Thus, any possibility of liquid leakage into the .bore of the mandrel except through the valve seat 62 is precluded.

The mandrel carries a plurality of internal, longitudinally extending, shouldered ribs 68 in its rearward portion, the ribs extending forwardly from the ange 60 and terminating beneath the rearward portion of the expander drum 43 in rearwardly facing shoulders 69. A ilanged sleeve 7d is received upon the shoulders 69 and surrounds the forward end of a cylindrical valve member 71. The rearward face of the valve 71 is anged and carries a beveled, resilient valve seat engaging element 72 constantly urged against the valve seat 62 by a coiled spring 73 conned between the flange of the valve member and the ange of the sleeve 70. Thus7 `at all times, the spring 73 urges the valve element 72 into a closed position.

For locking the valve in a closed position, dogs or bell crank levers 'i4 are pivotally mounted upon the rearward ends of the ribs 68 and carry rollers 75 projecting through windows 76 in the mandrel 2i into the path of the rearwardly moving sleeve 34. Upon rearward movement of Vthe sleeve 34, the rollers 75 are engaged and forced in wardly through the windows 76 into the interior of the mandrel 21, thus swinging pressure rollers 77 against the bottom of the valve member 7 i and locking the valve in a closed position. To provide for small inaccuracies of manufacture, the bottom of the Valve element 7i is made slightly resilient in nature by a resilient disc 78 clamped thereto by `a bumper plate 79 which is engaged by the pressure rollers 77. With this structure, a slight over travel of the pressure rollers 77 is permitted since the disc 78 will yield under the excessive pressure and will permit the bumper plate 79 to move closer to the bottom of the valve element 71. To limit the rearward travel of the sleeve 34, the mandrel 21 is provided with an external shoulder 8i) rearwardly of the windows 76 and against which the rearward edge of the sleeve will abut to limit rearward movement thereof.

There is shown in Figs. 4 through 7 a structure for engaging the gear 38 of lthe plug and selectively expanding or contracting the plug. The plug operating mechanism includes a tubular housing 81 carrying a pipe llange 82 at one end and a. transverse head 33 at its opposite end. There is also an internal transverse partition S4 spaced from the flange end of the housing.

A gear carriage 85 projects from the housing and is carried upon a tubular support member S6 passing through a packing gland 87 in the partition 84. A jack screw 88 is screwthreadedly received within the member 86 and has its outer end carried in a thrust bearing 89 mounted in the head 83. A wrench head 90 upon the outer extremity of the jack screw projects outwardly of the head 83 and makes provision for selective rotation of the jack screw to advance or retract the tubular support member 86 through the partition 84 to extend the gear carriage from the housing 81, or to retract this gear structure into the housing 81 between the flange 82 and the partition 84.

The gear carriage 85 includes a pair of spaced parallel cheek plates 91 joined at one end by a transverse head 92 to which the support member 86 is secured. A transverse web 93 spaces the medial portions of the cheek plates and carries in an end bearing 94 the lower end of `an operating shaft 95. The shaft 95 also passes through a bearing 96 in the head @2 and is keyed to a tubular extension 9"! projecting into the housing 31 through a packing gland 93 in the partition 8d similar to the gland 5.57. The outer end 99 of the tube i7 is polygonal in cross-section telescopes the polygonal bore 1%() ot driving tube 16?.. The outer end of the driving tube is carri-cd within a bearing member 1li?. supported in the head S3, and a wrench head .193 projects beyond the bearing for ec a suit-able tool and rotation of the tubes lll'. o $7.

The shaft Sie', which is revolved by means of the tubes 97 and 101, has a worm gear 1111i lformed thereon intermediate the bearings 9d and 9e, and engages a worm wheel 1&5 positioned between the cheek plates 91 upon a shaft lilo journaled in the cheek plates on bearings .tl' and projecting outwardly beyond said plates. A chain sprocket 103 is mounted upon each end of the shaft lilo outwardly or" the pl tes 91.

A gear .159, adap s. to engage the gear Sti, is mounted upon a shalt outwardly of the. web il between 'the cheek plates il and projects beyond the ends of said plates. The shaft ills is carried upon bearings 111 suitn ably recessed in the cheek plates and has chain sprockets 112 upon each end outwardly of the cheek plates. Suitable driving sprocket chains 113 lie along the outer face of each of the plates 9'1 and encircle the sprockets lll@ and 119. Thus, as the worm wheel 1655 is driven by the worm gear 104, the sprocket chains 113 are driven to cause revolution of the gear 1li? and the transmission of rotative power to the gear 38.

The telescopic mounting of the polygonal head 99 of the driving tube 97 permits the inward and outward movement of the tube 97 within the tube 1151 without the loss of means for transferring rotative motion from the wrench head 03 to the gear 169. Operation of the jack screw 38 by the wrench head 9? results in the extension or retraction of the gear structure 85.

In the utilization of the method of this invention, and the structures disclosed herein, one or more of the plugging devices are introduced into the pipe line in the mauner described in Figs. 8 and 9 and pumped to the location in the pipe line at which a closure is desired. Assuming that it is desired to isolate a short section of the pipe line, the pipe line will have been drilled into at the proper location without loss of pressure by means of drilling machines such as that shown in the patent to Field, No. 1,743,338. in accordance with this standard and well known practice, and referring to Fig. l, a short flanged nipple 114 is welded to the outer wall of the pipe line 19, and a fully opening valve such .as a gate valve 115 is secured thereto. With the valve 115 closed, apipe tapping or tap drilling device is secured to the opposite side of the valve 115 in pressure-tight relationship, the valve is then opened and the pipe tapping drill advanced through the valve so as to cut la hole 116 in the wall of the pipe within the nipple 1.14. Desirably, a blind or bull plug 117 will have been welded to the pipe diametrically opposite the nipple 115i, and the drilling device may be advanced entirely across the pipe to drill an opening 11S in the wall thereof diametrically opposite the opening 116.

The drilling device is then retracted, and the valve 115 is closed, after which the drilling device may be disconnected without loss of pressure or lluld from the pipe line.

This same operation is carried out at a point spaced sufficiently from the openings 116 and 11.8 to introduce into the pipe line additional lateral openings 119 and 129 spaced from the openings 116 and 118 a distance approximately equal to the length of the plugging device. Also, `at a point between the openings 116 and 119 proper to bring the same into alignment with the gear 33 when the plug is in position, an additional nipple 121 and valve 122 is connected to the pipe, and an opening 123 drilled through the wall of the pipe for reception of the actuating device shown in Fig. 4.

The same operation is carried out on the pipe line at the point at which the second closure or seal is desired, there being thus secured to the pipe the nipple 122 carrying the valve 123 and permitting access to diametrically opposed openings 124 `and 125, the nipple 126 carrying the valve 127 for access to the opening 123 through which the actuating device may be inserted, and the nipple 129 carrying the `valve 13b and permitting access to the openings 131.

Before the first plugging device A reaches the area to e sealed a blocking bar 132, by means of a pressure-tight housing, is lowered through the valve .115 into the openings 116 and E13 so as to provide a transverse barrier in the pipe line l@ without obstructing materially the passare or" liquid therethrough. The valve 115 is then closed and the bar introducing housing, which may be cuite similar in structure to the drill advancing means of 'the Field patent, is disconnected.

As the plugging device A reaches 'the blocking bar, the forward striker plate 33 of the plugging device engages the bar 132 and further movement of the device is prevented. Since the valve element 72 of the plugging device is not yet in its locked position, however, lluid may continue to pass through the plugging device and through the pipe line. due to its forced compression of the spring 73 and the unseating of the element 72 from the seat 62.

Following the positioning of the rst plugging device A, a second blocking bar 133 is dropped into position through the openings il? and 12d to prevent rearward movement of the plugging device A when the pipe liuc is opened. Also, a blocking bar 134 is dropped into the openings 124 and 125 for reception for the second plugging device B which is then pumped through the pipe line and into position against the 'bar 13d. A fourth blocking bar 135, placed in position in the openings 131, likewise prevents reverse travel of the second plugging device B.

With both plugging devices in place, the pumping or" fluid through the pipe line may be terminated, and both plugging devices expanded or set in position to isolate the section of pipe line therebetween. Up until this point, neither of the plugging devices or their blocking bars have materially impeded the flow of liquid through the pipe line and substantially normal pumping operations, or at least pumping operations adequate to move the plugging devices into place, may be continued. Referring now to Fig. 4, the plug actuating device illustrated therein, with its gear mechanism 5 .retracted into the housing 81 between the lange 82 and the partition 84, is joined onto the outer flange of :the valve 122 by the flange 82 of the actuating device, the valve 12.2 is opened, and the gear mechanism advanced into engagement with the gear 38 of the plug A for the transmission of rotating torque thereto.

As the gear 3S is revolved around the mandrel 2l, of the plugging device, the threaded collar 35 causes the sleeve 34 to advance toward the rearward end of the plugging device and force the tapered or conical expander drum 43 into the tapered bore 44 of the sealing rubber 45. The bolts 35 prevent rotation of the sleeve 34 with the collar 35, the frictional engagement of the cups 27 and 52 with the inner wall of the pipe line being adequate to hold the mandrel 21 itself against revolution within the pipe line. Thus, the plugging device A is expanded into its sealing position, as illustrated in Fig. 3, the sealing rubber i5 being tightly and snugly distorted between the inner wall of the pipe 1i? and the outer conical surface ot' the expander drum 43 to provide a complete seal. The gaskets 55 and 63, along with the O-ring 66 and the sealing ring 53, prevent any bypassing of fthe sealing rubber land insure a complete seal.

At the same Itime that the expander drum is advanced into the sealing rubber, the rearward end of the sleeve 34 is caused to ride over the rollers 75, thus forcing the rollers inwardly through the window 76, swinging the bell crank levers 74, and forcing the rollers 77 against the plate '79. This operation locks the valve element `72 securely against its seat 62 4and completes the transverse closure of the pipe line.

The same operation is carried out with the plugging device B by retraction of the actuating device of Fig. 4, disconnection thereof from the valve 122 and connection to -the valve 127. A suitable tap may then be made into the section C of the pipe line enclosed between the plugging devices A and B, the iiuid drained therefrom and conserved, the pipe line repaired, modified, or other wise altered as desired.

Following completion of the repairs or modifications, the plugs are removed by reversal of the above process, the actuating device being extended into the pipe line to engage the gear 109 with the gears 38, the gear 109 revolved in the opposite direction to withdraw the expander drum 43 from beneath the packing rubbers 45 and release or contract the plugging devices A and B from their sealing positions. Then, the blocking bar 132 may be removed and the plug A pumped down the pipe line for removal therefrom in the receiving trap 12'. The plug B, having been released and its internal valve having been unlocked, will permit the passage of fluid for this operation, but the plug B is prevented from downstream movement because of `the blocking bar 134 which is still in place.

After retrieving the plug A from the pipe line, the blocking bars 133, 134, 135 may be removed and -the plug B transported down the pipe line to the receiving trap 12' for removal. All of the valves 115, 122, 123', 7127 and 130 may be closed and left in place, or the nipples 114, 121, and so forth may carry internal screw threads into which a solid plug may be screwed, followed by removal of the valves and the securing of a blind iiange or other inexpensive closure element to the outer ends of the nipples.

lt is pointed out that the valves required for the side tapping operation of the pipe line are relatively small and inexpensive as compared to the valves required for the pipe line itself, and whether or not such smaller valves are salvaged, a material saving is elected. For reasons of illustration, the drawings do not show the pipe line and the side taps thereinto in exact proportion since this method and these structures are usable upon pipe lines of any diameter.

l't is to be noted that the method and means may be employed on pipelines handling any type of fluid, such as natural gas, even though they iind their greatest eiectiveness and economy in use on lines handling liquid materials. It is further to be noted that the plugs may be modified for use in diierent diameter pipes by a simple changing of the rubber 45 and the cups 27 and 51, accompanied by replacement of the ring 47 by one of larger diameter and possibly the removable attachment of a ilange ring to the forward end of the cone 43.

The foregoing description of the invention is explanatory thereof and various changes in the size, shape and materials, as well as in the details of the illustrated construction and the described method may be made, within the scope of the appended claims, without departing from the spirit of the invention.

What l claim and desire to secure by Letters Patent l. A pipe line plug including, a central support, pipe engaging cups on the support, a packing member on the support, means movable longitudinally of the packing member for expanding the same radially, said means having a screw-threaded portion, an actuating collar having screw-threaded engagement with the expanding means for moving the latter longitudinally of the packing m-ember, and external gear teeth on the collar exposed laterally of the plug whereby said gear teeth maybe engaged by means for revolving the actuating collar introduced laterally of the plug.

2. A pipe line plug including, a central support, pipe engaging cups on the support, a packing-member on the support, a cone movable longitudinally of the packing member for expanding the same radially, said cone having a screw-threaded portion, and an actuating collar having screw-threaded engagement with the expanding cone for moving the latter longitudinally of the packing member, and external gear teeth on the collar exposed laterally of the plug whereby said gear teeth may be engaged by means for revolving the actuating collar introduced laterally of the plug.

3. A pipe line plug as set forth in claim l, wherein the central support has an axial passage, and a pressure relief valve normally closing said passage.

4. A pipe line plug as set forth inclaim 3, resilient means urging said valve toward a closed position, locking means movably mounted in the plug for locking the valve closed, and actuating means for the locking means engaged by the expanding means anddisposed in the path of longitudinal movement of the expanding means.

5. A pipe line plug as set forth in claim 1,'and a rekmovable actuating device for the plug adapted to be inserted through the wall of a pipe, the ldevice including, a gear wheel adapted to engage and revolve the actuating collar, means for revolving the gear wheel, a telescoping bar supporting the gear wheel, and means for telescoping the bar to retract the gear wheel.

6. A pipe line plug as set forth in claim l, and a removable actuating device for the plug adapted to be inserted through a closure into a pipe, the device including, a housing adapted to be connected to the closure in pressure-tight relationship, a partition in the housing, a supporting bar extending through the partition, an operating shaft extending through the partition, pressure seals on the partition around the bar and the shaft, means for moving the bar through the partition, a gear wheel carried by the bar and adapted to engage and revolve the actuating collar, and means connected to the shaft for revolving the gear wheel.

7. A pipe line plug including, a central support, pipe engaging cups on the support, an expansion cone movable longitudinally on the support, means holding the cone against revolving on the support, an annular packing member having a tapered bore receiving the cone, an actuating collar having screw-threaded engagement with the cone for moving the latter longitudinally, means limiting longitudinal movement of the collar and the packing member, and means for revolving the collar.

8. A pipe line plug as set forth in claim 7 wherein the pipe engaging cups are disposed at each end of the support, and the actuating collar and packing member are confined therebetween so as to be protected thereby.

9. A pipe line plug as set forth in claim 8, wherein the outside diameters of the actuating collar and the packing member are less than the diameter of the cups.

10,.A pipe line plug including, a central support, pipe engaging cups on the support and held against rotation thereon, an expansion cone movable longitudinally on the support, means holding the cone against revolving on the support, an annular packing member having a tapered bore receiving the cone, an actuating collar having screwthreaded engagement with the cone for moving the latter longitudinally, means limiting longitudinal movement of the collar and the packing member, and means for revolving the collar.

lll. As a sub-combination, an actuating device for a plpe line plug, said device including, an open-ended housing, a partition in the housing, a supporting bar and an operating shaft extending through the partition, pressure seals on the partition around the bar and shaft, a plugengaging litting on the bar in the open end of the housing, means carried by the shaft for powering said iitting, and means in the bar for projecting the iitting from the open end of the housing.

12. As a sub-combination, an actuating device for a pipe line plug having a circumferentially-rotatable mem- Weense ber, said device including, an open-ended housing, a partition in the housing, a supporting bar and an operating shaft extending through the partition, pressure seals on the partition around the bar and shaft, a rotatable plugengaging fitting on the bar in the open end of the housing` means carried by the shaft for rotating said fitting, and means for extending the bar to project the fitting from the open end of the housing.

13. A pipe line plug as set forth in claim 7, wherein the central support has an axial passage, a valve seat in the passage, a valve element adapted to engage the seat, and resilient means urging the valve element toward the seat, the valve element opening from the seat in such direction as to receive excessive pressure from the cups.

14. A pipe line plug as set forth in claim 7, wherein the central support has an axial passage, a valve seat in the passage, a valve element adapted to engage the seat, and resilient means urging the valve element toward the seat, dogs Pivo-tally mounted on the support and pivotally movable into engagement with the valve element to lock the valve element on the seat, and means carried by the dogs engaged by the cone in the longitudinal movement of the cone for pivotally moving the dogs into engagement with the valve element.

15. A pipe line plug as set forth in claim 7, wherein the central support has an axial passage, a valve seat in the passage, a valve element adapted to engage the seat, and means constantly urging the valve element toward the seat, bell crank levers pivoted in the passage of the support, the support having openings through which one arm of each of the levers projects into the path of movement of the cone, the other arm of each lever underl?. lying the valve element forv engagement with the valve element to lock the same on the seat when the cone moves longitudinally over the openings.

16. The method of closing oft' a large diameter pipe iine at a selected point including the steps of, cutting i1 small diameter opening in the Wall or" the pipe at the selected point, introducing a plug -stopping element into the pipe through the opening, introducing an expansible pipe plug into the pipe at a point removed from the selected point of closure, transporting the plug through the pipe te the stopping-element by flowing liuid through the pipe, and expanding the plug at the selected point of closure into sealing engagement with the Wall of the pipe.

l17. The method of closing oil a section of a large diameter 'pipe line including the steps of, introducing a iii'st plug stopping element into the pipe line at the do'vvnstream end of the pipe line section, flowing a first expansible plug through the pipe line in a body of huid to the first stopping element, introducing a `second plug stopping element into the pipe line at the upstream end of the pipe line section, owing a second expansilile plug through the pipe line in a body of uid to the second stopping element, and expanding both plugs to seal off the section of pipe line.

References Cited in the file of this patent UNITED STATES PATENTS 

